


Dust to Dust

by Anonymonimus



Category: Undertale (Video Game)
Genre: Alternate Universe - Zombie Apocalypse, Angst, Angst and Hurt/Comfort, Brotherly Affection, Brotherly Angst, Brotherly Love, Character Death, Death, Emotional Hurt, Emotional Hurt/Comfort, End of the World, Fontcest, Gen, Grief/Mourning, Heavy Angst, Hurt, Hurt No Comfort, Hurt/Comfort, Implied/Referenced Character Death, M/M, Sad, Sad Ending, Sans-centric, Unhappy Ending, Zombie Apocalypse, it can be seen as totally platonic, on that note, this isnt automatically fontcest
Language: English
Status: Completed
Published: 2016-10-21
Updated: 2016-10-21
Packaged: 2018-08-23 19:58:09
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings, Major Character Death, No Archive Warnings Apply
Chapters: 1
Words: 3,002
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8340787
Author URL: https://archiveofourown.org/users/Anonymonimus/pseuds/Anonymonimus
Summary: When monsters were told the legend of the Angel of Death, no one imagined it would come under the form of a disease riddled child.





	

**Author's Note:**

> **Requested by nagisaheichou in the midst of discussing really depressing, heartbreaking scenarios in which to put the skelly bros.**
> 
> **We both really liked this one xP**
> 
> **I hope you ENJOY, friend!**

When monsters were told the legend of the Angel of Death, no one imagined it would come under the form of a disease riddled child. They fell into the Ruins first, infecting and destroying any monster foolish enough to cross their path. Rumour had it that long lost Queen Toriel had exiled herself to that particular location after her falling out with her husband. Sans always thought she had been the woman behind the door; guarding the Underground and deciding who could pass and who could not. He couldn't imagine she was still alive or still herself seeing as the child had eventually crossed the door.

The few monsters that had managed to escape the Ruins before the child finally made their way out had been able to warn the inhabitants of Snowdin. As such, the child eventually met their end at the hands of Undyne the Undying. Unfortunately, by then, the damage had been done and it was too late. The virus they had spread upon falling changed those who had had the misfortune of being infected. It took two wretched days for the infected to fall horribly ill and die without turning to dust. Hours after their deaths, they would rise again as mindless killing machines.

Sans had barely been able to escape with Papyrus and Undyne by the time he realised what was going on. The last two loathed to leave innocent monsters behind to be slaughtered, but they had no choice. They had to run. And so they fled to Alphys's laboratory in Hotland. With her multiple cameras installed throughout the Underground, she had been able to witness the massacre of Snowdin and make a safe haven of her home. She accepted monster refugees by the hundred – the last of which were Sans, Papyrus, and Undyne.

As customary upon entering the premises, each were subjected to an evaluation from Alphys to make sure they hadn't somehow gotten infected. It was then they learned Undyne had been bitten by one of the changed monsters while they were fleeing Snowdin. For the sake of the remaining monsters, Undyne left the laboratory of her own accord. She swore to slay as many of the corrupted as she could in the hopes that they would later be able to regain the lost territory through her final act of help. No one knew how terrible of a mistake it had been to let her go until she turned.

A changed Undyne returned to the laboratory flaring with rage and awesome power two horrible days later. The doors to the laboratory were easily busted down and in flooded blood-hungry corrupted monsters. Alphys did her best to save as many as she could, ordering people to retreat to the True Lab. Only two dozens of them made it. They barricaded themselves in with what they could, but everyone knew it was only a matter of time before the corrupted would break through and slaughter them all. What made matters worse was that three different monsters locked in with them were also infected and there were no means for anyone to escape. One way or another, it seemed, they would die.

While the frightened monsters tried to come to grips with their inevitable deaths, if not by the hoard outside then by the ticking time bombs indoors, Sans opted to try something. He killed the three infected monsters with the hypothesis that the action would either speed up the change and their own subsequent deaths, or they would turn to dust. Fortunately, it was revealed to be the latter scenario. An infected monster could be prevented from changing if they were killed while still themselves.

Though a certain sense of relief had washed over the remaining survivors, a threat still loomed at their door as they were reminded with every frightening blow to it. Sooner or later, they would break through. If it happened to be later, than the issue of food and water would bring about their speedy deaths. There was nothing to eat in the room in which they had locked themselves. But, as it was, they didn't have to worry about the threat of starvation and dehydration.

At the time, Papyrus was doing his best to keep the morals up as he preached pointless words of hope that someone would come save them. Surely King Asgore had heard about what had transpired and had organised the King's Guard to counter the threat. They just had to wait and someone would come save them. But nobody came. Sans usually kept his eyes trained on his brother. The merciless blunting against the door kept him on high alert, but after a week of listening to it, he had grown accustomed to it and unfortunately let his guard down. He glanced away and began to doze off to sleep.

And then the door finally broke down.

Without the slightest form of warning, the door and the barricade was blown aside and chaos ensued almost immediately. Corrupted monsters littered the grounds, attacking and devouring the helpless remaining monsters. The shrieks and howls that erupted were deafening but all Sans could hear or see was his brother, Papyrus, who was too far away. For the first time, without care for what anyone else who saw him would say or think, he used his special magic. He teleported to his brother, he grabbed him, and he teleported away; abandoning Alphys and the others to a terrible fate.

Sans teleported back to their home in Snowdin. Their house had been ransacked and destroyed. The windows were broken, the door was destroyed, and their living space was a complete, gruesome mess. Despite all of that, there were no corrupted monster nearby. Sans thus helped Papyrus through the door and lead him up the stairs into his room. His cool bed was in tatters but it was good enough so he helped him lie down and finally took a look at the horrible wound on his arm.

Papyrus winced as Sans carefully examined the incredible bite mark that had shattered his ulna and radius. Bone marrow seeped through the cracks, dripping onto Sans's smaller, shaking hands and staining the sleeve of his blue sweater. Papyrus had been bitten. He had been too far away for Sans to reach in time. Papyrus had been bitten. And Sans struggled to accept what that meant.

"Sans…" Papyrus breathed grimly. Sans's head snapped up, meeting his brother's gaze. "How did you…how did you bring us here?"

Sans was taken aback by the question. He wasn't quite sure how to answer it. "i…uh…i have very powerful magic." He explained loosely, avoiding to elaborate on the whole truth, "so i can, you know…teleport…"

Papyrus glared at him with absolute rage and anger. "Why didn't you do that before?" He demanded, struggling to keep a relatively calm tone. "You could have saved everyone."

Sans looked down guiltily. "it's not that simple, pap." He countered, "i couldn't just teleport willy-nilly when i had no idea if the place i chose would be infested with the corrupted…"

"You could have done something!" Papyrus insisted, letting anger seep into his tone. Tears built at his eyes and his agitated state caused more bone marrow to seep out of his wound, "You could have lead them away! You could have distracted them! You…you…" his words shrank into silence. For a moment, neither said a thing until Papyrus lowered his head and muttered: "I'm…going to become one of them now…"

"no." Sans said stiffly, "you're not."

"Are you going to kill me too?" Papyrus asked bitterly. Where most of the survivors, including Alphys, thanked Sans for having done what he did, Papyrus had disagreed entirely. He didn't think Sans had been in the right to have done what he did even if it had saved his life.

"i'm going to save you." Sans stated.

"How?"

Sans honestly wasn't sure. But he was going to find a way. He had to.

Luckily for him, they were back home and so Sans had his hidden lab at his disposal. There he would surely have the required equipment to stunt the virus and later eradicate it entirely. That being said, two days was an incredibly tight deadline to work with so he had to work very diligently.

The first thing Sans tried was cutting off Papyrus's wounded arm entirely. He rationalised that if he removed the infected body part, perhaps he could spare his brother from the virus. The taller skeleton had sufficient hp to survive the procedure and so he wasted no time in performing it. Unfortunately, six hours later, Papyrus began exhibiting symptoms of the illness the infected suffered from before turning.

His next move was to pump Papyrus full of as many antibiotics as he could gather. As such, Sans raided the ruined Snowdin shops and quickly teleported to Asgore's castle in New Home for stronger drugs. While he was there, he spotted New Home burning from one of the nearby windows as the corrupted monsters ravaged the city. He didn't see Asgore during his short trip and could only imagine the king had gone to try to defend his people. Sans was reasonably certain he wouldn't succeed in his endeavour and shortly returned to Papyrus. He consequently monitored Papyrus using the machines he stored in his hidden lab and anxiously waited for the antibiotics to take effect. Papyrus's condition continued to deteriorate and, six more hours later, Sans concluded this new strategy had failed.

The last thing he could think to do was study the virus to determine a weak point. As Papyrus continued to get sicker and the deadline reached its end, Sans didn't feel remotely comfortable being away from his brother for extended periods of time. He moved him to the hidden lab so as to watch over him while he worked. Papyrus was in awe of the area and most likely had a lot of questions for Sans, but he was far too sick to ask let alone listen to the answers. In the end, he let his brother work knowing they were running out of time.

Sans worked relentlessly in an attempt to quickly understand the virus. He observed the way it seemed to attack cells and found it to be unlike anything that had ever been recorded by monster or men. It seemed to reproduce by injecting its DNA into a cell, but where this would normally result in the death of the infected cell, instead it continued to thrive despite being partially turned to dust. The situation was indeed complex but Sans refused to face the facts in regards to solving the virus. That was, until there were only less than an hour left for Papyrus.

"Sans…" The skeleton called weakly from his corner in the lab. "Stop it…it's no use. We're out of time…"

Where Papyrus's bones had once been a bright and healthy white, the virus had turned it into a sickly greyish-yellow. He clutched at the blanket wrapped around his shoulders feebly, unable to maintain a strong grip on the fabric. He was sweating profusely, fat beads of sweat rolling down his skull and dirtying his clothes. Sans initially thought his brother might have been too hot with the blanket, but when he tried to remove it, Papyrus claimed he was freezing.

"i'm not giving up." Sans declared. He shot up from his seat and marched to the stack of antibiotics a few short feet away from Papyrus. He grabbed a few different ones and brought them to the taller skeleton. "take these."

"No." Papyrus refused.

"pap—"

"It's over, Sans." Papyrus interrupted firmly. "I'm dying – in fact, I might as well be already dead."

"don't say that." Sans insisted, pushing the antibiotics towards his brother, "just take these. they'll help."

"They won't." Papyrus stubbornly countered. "Otherwise they would have done something the first time I took them."

"pap, i know this isn't fun," Sans desperately tried to convince him to rethink his refusal, "but you've got to do it. this is going to help you get better."

"Don't do this, Sans." Papyrus sighed, "Don't cling to fantasy like that."

Sans snapped his mouth shut and clutched the bottles of antibiotics tightly in his hands. "wh…what else am i supposed to do?" He asked, his voice trembling with grief. "am i supposed to just accept that you're going to die? that i can't save you? that i failed to protect you?"

"Yes." Papyrus answered bluntly. "You don't have a choice."

"i…" Sans tried, but choked. He was angry with himself, with his helplessness. He wanted to return to his task in studying the virus but the truth was that it would take him, at the very least, six months to come up with something substantial. "i can't do that, Papyrus."

"Yes, you can…" Papyrus insisted, "You're strong…Stronger than I ever imagined. I want you to live through this Sans. I want you to stop this – kill all the corrupted and save what's left of monster kind…starting with…me…"

Sans felt his heart tighten painfully as his body stiffened in horror. He backed away from Papyrus terribly frightened by what was being asked of him. "no…no, no, no, _no_!"

"I don't want to become corrupted." Papyrus said. "If you kill me now…I'll turn to dust like I'm supposed to. I don't…I don't want to hurt you, Sans…I need you to do this for me."

"i can't!" Sans shouted, "i'm not going to hurt you!"

"You need to!" Papyrus shouted back, "You need to live! _I_ need you to live!"

"do you know what you're asking me to do!?" Sans snapped, "you're asking me to kill someone i love – the only person that ever mattered to me…"

"Sans…" Papyrus breathed, calming his tone. "I'm going to die whether you do something or nothing. Let me die as myself. I'd…I'd kill myself for you, but I'm too weak…I can hardly move my body and, if I could, I don't think I'd have the nerve…"

"then how do you expect _me_ to have the nerve?" Sans retorted brokenly.

"Sans…stop it." Papyrus sighed, leaning his head back against the wall. "I'm running out of time…I can feel it…"

"then take the antibiotics." Sans demanded hopelessly.

"Kill me…" Papyrus begged instead. "Let me die as me…If you love me, you'll do it…and you won't argue with me anymore either. I don't want my last conversation with you to be an argument."

"papyrus…" Sans breathed, tears welling in his eyes.

This was the end, wasn't it?

"The world went mad very suddenly, didn't it?" Papyrus asked rhetorically, an empty smile on his face, "One moment, everything was nice and fine…the next, everyone was dying. I don't…I don't understand, Sans…what did we monsters ever do that was so horrible, we deserved to be locked away in the Underground and now subjected to some insane sickness? Why us? What did we do?"

"life's not fair, papyrus." Sans commented numbly.

"Maybe…" He agreed tentatively. "I…I wish I could have seen the surface…Do you remember what we always talked about doing if we ever got out of here…?"

Sans scoffed, a fat tear rolling down his cheek as he did so. "of course i do."

"We were…" Papyrus started, eyes unfocused, "We were going to explore the world…I was going to drive a car down the highway, from one ocean to another…At night, we were going to contemplate the stars – the real ones…maybe we could have convinced some human scientists to let us use their special telescopes to get a better look…"

Sans began to cry. "a-and what else?" he stammered through the tears, "what would we explore?"

"Human culture, naturally!" Papyrus responded vivaciously despite his rapidly deteriorating state. He seemed so weak and the life in his eyes was quickly fading. He probably only had a few minutes left. "They're so…interesting…monsters are the same from one part of the Underground to the other but they…the humans…they're so varied…it's really something…so we would…we would explore the whole world…maybe we would get a house in Italy…away from cities and by the sea…we would have a really clear view of the stars at night there…"

"we would, hun…?" Sans hiccupped, wiping the tears from his face with his sleeve.

"Hey, Sans…?" Papyrus said weakly, "I love you."

"i-i love you too bro." he replied.

Papyrus smiled as he shut his eyes, then he expelled his last breath and he was dead. Sans curled in onto himself when he realised his brother was truly gone. He cried loudly, cursing himself for not having found a way to save him. Had he just been more vigilant, more on guard, he would have been able to save Papyrus when the door finally broke down and the corrupted flooded the room. But Sans had instead made a mistake, one he would have to live with…fortunately, not for much longer.

A few hours of crying and lamenting Papyrus later, the corpse of the latter began to stir as life filled it once more. The monster slowly rising from its slumped position was no longer his brother despite sharing the same body. Sans would have to kill it in order to live, but he knew that he couldn't do it. He couldn't and he didn't want to. The world had gone to shit. The Underground was in ruins and it was very likely that monster kind had already been annihilated. Sans was probably the last left and if he wasn't, it didn't make a difference as they would soon be extinct anyway.

So when Papyrus rose from the dead with an animalistic rage and set his gaze upon him, Sans opened his arms and welcomed the set of fangs that ferociously cracked through his bones.


End file.
